Synthesis and characterization of tetravalent titanium (Ti4+) substituted LiCoO2 for lithium-ion batteries

Several substitutions on layered lithium cobaltate were attempted and reported as a cathode material for secondary lithium rechargeable batteries. The tetravalent titanium substitution on LiCoO2 having composition LiCo1-zTizO2 (z = 0.00, 0.25 and 0.50) was prepared by a solid-state reaction method, which reveals an ordered rock salt structure of alpha-NaFeO2 type. The synthesized cathode materials were examined through TG/DTA, Xray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM) and particle size analyzer. Electrochemical characterizations of the synthesized material were characterized through cyclic voltammogram (CV) and life cycle tester in the voltage range of 2.7-4.2 V. The cell behaviour of LiCo1-zTizO2 (z = 0.25 and 0.50) was slightly better than that of LiCoO2 in terms of voltage plateau and reduced fade in capacity during charge/discharge process. LiCoO2 delivers a charge capacity of 142 mAh g(-1) with the loss of 5% during discharge, while Z = 0.25 in LiCo1-zTizO2 gave 135 mAh g(-1) with the loss of 8%. (c) 2006 Elsevier B.V. All rights reserved.